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Autoload calendar-setup.
[gnu-emacs] / lisp / calendar / holidays.el
1 ;;; holidays.el --- holiday functions for the calendar package
2
3 ;;; Copyright (C) 1989, 1990, 1992, 1993, 1994 Free Software Foundation, Inc.
4
5 ;; Author: Edward M. Reingold <reingold@cs.uiuc.edu>
6 ;; Keywords: holidays, calendar
7
8 ;; This file is part of GNU Emacs.
9
10 ;; GNU Emacs is free software; you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation; either version 2, or (at your option)
13 ;; any later version.
14
15 ;; GNU Emacs is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
19
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs; see the file COPYING. If not, write to
22 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
23
24 ;;; Commentary:
25
26 ;; This collection of functions implements the holiday features as described
27 ;; in calendar.el.
28
29 ;; Comments, corrections, and improvements should be sent to
30 ;; Edward M. Reingold Department of Computer Science
31 ;; (217) 333-6733 University of Illinois at Urbana-Champaign
32 ;; reingold@cs.uiuc.edu 1304 West Springfield Avenue
33 ;; Urbana, Illinois 61801
34
35 ;; Technical details of all the calendrical calculations can be found in
36 ;; ``Calendrical Calculations'' by Nachum Dershowitz and Edward M. Reingold,
37 ;; Software--Practice and Experience, Volume 20, Number 9 (September, 1990),
38 ;; pages 899-928. ``Calendrical Calculations, Part II: Three Historical
39 ;; Calendars'' by E. M. Reingold, N. Dershowitz, and S. M. Clamen,
40 ;; Software--Practice and Experience, Volume 23, Number 4 (April, 1993),
41 ;; pages 383-404.
42
43 ;; Hard copies of these two papers can be obtained by sending email to
44 ;; reingold@cs.uiuc.edu with the SUBJECT "send-paper-cal" (no quotes) and
45 ;; the message BODY containing your mailing address (snail).
46
47 ;;; Code:
48
49 (require 'calendar)
50
51 (autoload 'solar-equinoxes-solstices "solar"
52 "Date and time of equinoxes and solstices, if visible in the calendar window.
53 Requires floating point."
54 t)
55
56 (defun holidays (&optional arg)
57 "Display the holidays for last month, this month, and next month.
58 If called with an optional prefix argument, prompts for month and year.
59
60 This function is suitable for execution in a .emacs file."
61 (interactive "P")
62 (save-excursion
63 (let* ((completion-ignore-case t)
64 (date (if arg
65 (calendar-read-date t)
66 (calendar-current-date)))
67 (displayed-month (extract-calendar-month date))
68 (displayed-year (extract-calendar-year date)))
69 (list-calendar-holidays))))
70
71 (defun check-calendar-holidays (date)
72 "Check the list of holidays for any that occur on DATE.
73 The value returned is a list of strings of relevant holiday descriptions.
74 The holidays are those in the list calendar-holidays."
75 (let* ((displayed-month (extract-calendar-month date))
76 (displayed-year (extract-calendar-year date))
77 (h (calendar-holiday-list))
78 (holiday-list))
79 (while h
80 (if (calendar-date-equal date (car (car h)))
81 (setq holiday-list (append holiday-list (cdr (car h)))))
82 (setq h (cdr h)))
83 holiday-list))
84
85 (defun calendar-cursor-holidays ()
86 "Find holidays for the date specified by the cursor in the calendar window."
87 (interactive)
88 (message "Checking holidays...")
89 (let* ((date (calendar-cursor-to-date t))
90 (date-string (calendar-date-string date))
91 (holiday-list (check-calendar-holidays date))
92 (holiday-string (mapconcat 'identity holiday-list "; "))
93 (msg (format "%s: %s" date-string holiday-string)))
94 (if (not holiday-list)
95 (message "No holidays known for %s" date-string)
96 (if (<= (length msg) (frame-width))
97 (message msg)
98 (set-buffer (get-buffer-create holiday-buffer))
99 (setq buffer-read-only nil)
100 (calendar-set-mode-line date-string)
101 (erase-buffer)
102 (insert (mapconcat 'identity holiday-list "\n"))
103 (goto-char (point-min))
104 (set-buffer-modified-p nil)
105 (setq buffer-read-only t)
106 (display-buffer holiday-buffer)
107 (message "Checking holidays...done")))))
108
109 (defun mark-calendar-holidays ()
110 "Mark notable days in the calendar window."
111 (interactive)
112 (setq mark-holidays-in-calendar t)
113 (message "Marking holidays...")
114 (let ((holiday-list (calendar-holiday-list)))
115 (while holiday-list
116 (mark-visible-calendar-date
117 (car (car holiday-list)) calendar-holiday-marker)
118 (setq holiday-list (cdr holiday-list))))
119 (message "Marking holidays...done"))
120
121 (defun list-calendar-holidays ()
122 "Create a buffer containing the holidays for the current calendar window.
123 The holidays are those in the list calendar-notable-days. Returns t if any
124 holidays are found, nil if not."
125 (interactive)
126 (message "Looking up holidays...")
127 (let ((holiday-list (calendar-holiday-list))
128 (m1 displayed-month)
129 (y1 displayed-year)
130 (m2 displayed-month)
131 (y2 displayed-year))
132 (if (not holiday-list)
133 (progn
134 (message "Looking up holidays...none found")
135 nil)
136 (set-buffer (get-buffer-create holiday-buffer))
137 (setq buffer-read-only nil)
138 (increment-calendar-month m1 y1 -1)
139 (increment-calendar-month m2 y2 1)
140 (calendar-set-mode-line
141 (if (= y1 y2)
142 (format "Notable Dates from %s to %s, %d%%-"
143 (calendar-month-name m1) (calendar-month-name m2) y2)
144 (format "Notable Dates from %s, %d to %s, %d%%-"
145 (calendar-month-name m1) y1 (calendar-month-name m2) y2)))
146 (erase-buffer)
147 (insert
148 (mapconcat
149 '(lambda (x) (concat (calendar-date-string (car x))
150 ": " (car (cdr x))))
151 holiday-list "\n"))
152 (goto-char (point-min))
153 (set-buffer-modified-p nil)
154 (setq buffer-read-only t)
155 (display-buffer holiday-buffer)
156 (message "Looking up holidays...done")
157 t)))
158
159 (defun calendar-holiday-list ()
160 "Form the list of holidays that occur on dates in the calendar window.
161 The holidays are those in the list calendar-holidays."
162 (let ((p calendar-holidays)
163 (holiday-list))
164 (while p
165 (let* ((holidays
166 (if calendar-debug-sexp
167 (let ((stack-trace-on-error t))
168 (eval (car p)))
169 (condition-case nil
170 (eval (car p))
171 (error (beep)
172 (message "Bad holiday list item: %s" (car p))
173 (sleep-for 2))))))
174 (if holidays
175 (setq holiday-list (append holidays holiday-list))))
176 (setq p (cdr p)))
177 (setq holiday-list (sort holiday-list 'calendar-date-compare))))
178
179 ;; Below are the functions that calculate the dates of holidays; these
180 ;; are eval'ed in the function calendar-holiday-list. If you
181 ;; write other such functions, be sure to imitate the style used below.
182 ;; Remember that each function must return a list of items of the form
183 ;; ((month day year) string) of VISIBLE dates in the calendar window.
184
185 (defun holiday-fixed (month day string)
186 "Holiday on MONTH, DAY (Gregorian) called STRING.
187 If MONTH, DAY is visible, the value returned is the list (((MONTH DAY year)
188 STRING)). Returns nil if it is not visible in the current calendar window."
189 (let ((m displayed-month)
190 (y displayed-year))
191 (increment-calendar-month m y (- 11 month))
192 (if (> m 9)
193 (list (list (list month day y) string)))))
194
195 (defun holiday-float (month dayname n string &optional day)
196 "Holiday on MONTH, DAYNAME (Nth occurrence, Gregorian) called STRING.
197 If the Nth DAYNAME in MONTH is visible, the value returned is the list
198 \(((MONTH DAY year) STRING)).
199
200 If N<0, count backward from the end of MONTH.
201
202 An optional parameter DAY means the Nth DAYNAME after/before MONTH DAY.
203
204 Returns nil if it is not visible in the current calendar window."
205 (let ((m displayed-month)
206 (y displayed-year))
207 (increment-calendar-month m y (- 11 month))
208 (if (> m 9)
209 (list (list (calendar-nth-named-day n dayname month y day) string)))))
210
211 (defun holiday-julian (month day string)
212 "Holiday on MONTH, DAY (Julian) called STRING.
213 If MONTH, DAY (Julian) is visible, the value returned is corresponding
214 Gregorian date in the form of the list (((month day year) STRING)). Returns
215 nil if it is not visible in the current calendar window."
216 (let ((m1 displayed-month)
217 (y1 displayed-year)
218 (m2 displayed-month)
219 (y2 displayed-year)
220 (year))
221 (increment-calendar-month m1 y1 -1)
222 (increment-calendar-month m2 y2 1)
223 (let* ((start-date (calendar-absolute-from-gregorian
224 (list m1 1 y1)))
225 (end-date (calendar-absolute-from-gregorian
226 (list m2 (calendar-last-day-of-month m2 y2) y2)))
227 (julian-start (calendar-julian-from-absolute start-date))
228 (julian-end (calendar-julian-from-absolute end-date))
229 (julian-y1 (extract-calendar-year julian-start))
230 (julian-y2 (extract-calendar-year julian-end)))
231 (setq year (if (< 10 month) julian-y1 julian-y2))
232 (let ((date (calendar-gregorian-from-absolute
233 (calendar-absolute-from-julian
234 (list month day year)))))
235 (if (calendar-date-is-visible-p date)
236 (list (list date string)))))))
237
238 (defun holiday-islamic (month day string)
239 "Holiday on MONTH, DAY (Islamic) called STRING.
240 If MONTH, DAY (Islamic) is visible, the value returned is corresponding
241 Gregorian date in the form of the list (((month day year) STRING)). Returns
242 nil if it is not visible in the current calendar window."
243 (let* ((islamic-date (calendar-islamic-from-absolute
244 (calendar-absolute-from-gregorian
245 (list displayed-month 15 displayed-year))))
246 (m (extract-calendar-month islamic-date))
247 (y (extract-calendar-year islamic-date))
248 (date))
249 (if (< m 1)
250 nil;; Islamic calendar doesn't apply.
251 (increment-calendar-month m y (- 10 month))
252 (if (> m 7);; Islamic date might be visible
253 (let ((date (calendar-gregorian-from-absolute
254 (calendar-absolute-from-islamic (list month day y)))))
255 (if (calendar-date-is-visible-p date)
256 (list (list date string))))))))
257
258 (defun holiday-hebrew (month day string)
259 "Holiday on MONTH, DAY (Hebrew) called STRING.
260 If MONTH, DAY (Hebrew) is visible, the value returned is corresponding
261 Gregorian date in the form of the list (((month day year) STRING)). Returns
262 nil if it is not visible in the current calendar window."
263 (if (memq displayed-month;; This test is only to speed things up a bit;
264 (list ;; it works fine without the test too.
265 (if (< 11 month) (- month 11) (+ month 1))
266 (if (< 10 month) (- month 10) (+ month 2))
267 (if (< 9 month) (- month 9) (+ month 3))
268 (if (< 8 month) (- month 8) (+ month 4))
269 (if (< 7 month) (- month 7) (+ month 5))))
270 (let ((m1 displayed-month)
271 (y1 displayed-year)
272 (m2 displayed-month)
273 (y2 displayed-year)
274 (year))
275 (increment-calendar-month m1 y1 -1)
276 (increment-calendar-month m2 y2 1)
277 (let* ((start-date (calendar-absolute-from-gregorian
278 (list m1 1 y1)))
279 (end-date (calendar-absolute-from-gregorian
280 (list m2 (calendar-last-day-of-month m2 y2) y2)))
281 (hebrew-start (calendar-hebrew-from-absolute start-date))
282 (hebrew-end (calendar-hebrew-from-absolute end-date))
283 (hebrew-y1 (extract-calendar-year hebrew-start))
284 (hebrew-y2 (extract-calendar-year hebrew-end)))
285 (setq year (if (< 6 month) hebrew-y2 hebrew-y1))
286 (let ((date (calendar-gregorian-from-absolute
287 (calendar-absolute-from-hebrew
288 (list month day year)))))
289 (if (calendar-date-is-visible-p date)
290 (list (list date string))))))))
291
292 (defun holiday-sexp (sexp string)
293 "Sexp holiday for dates in the calendar window.
294 SEXP is an expression in variable `year' evaluates to `date'.
295
296 STRING is an expression in `date' that evaluates to the holiday description
297 of `date'.
298
299 If `date' is visible in the calendar window, the holiday STRING is on that
300 date. If date is nil, or if the date is not visible, there is no holiday."
301 (let ((m displayed-month)
302 (y displayed-year))
303 (increment-calendar-month m y -1)
304 (filter-visible-calendar-holidays
305 (append
306 (let* ((year y)
307 (date (eval sexp))
308 (string (if date (eval string))))
309 (list (list date string)))
310 (let* ((year (1+ y))
311 (date (eval sexp))
312 (string (if date (eval string))))
313 (list (list date string)))))))
314
315 (defun holiday-advent ()
316 "Date of Advent, if visible in calendar window."
317 (let ((year displayed-year)
318 (month displayed-month))
319 (increment-calendar-month month year -1)
320 (let ((advent (calendar-gregorian-from-absolute
321 (calendar-dayname-on-or-before 0
322 (calendar-absolute-from-gregorian
323 (list 12 3 year))))))
324 (if (calendar-date-is-visible-p advent)
325 (list (list advent "Advent"))))))
326
327 (defun holiday-easter-etc ()
328 "List of dates related to Easter, as visible in calendar window."
329 (if (and (> displayed-month 5) (not all-christian-calendar-holidays))
330 nil;; Ash Wednesday, Good Friday, and Easter are not visible.
331 (let* ((century (1+ (/ displayed-year 100)))
332 (shifted-epact ;; Age of moon for April 5...
333 (% (+ 14 (* 11 (% displayed-year 19));; ...by Nicaean rule
334 (- ;; ...corrected for the Gregorian century rule
335 (/ (* 3 century) 4))
336 (/ ;; ...corrected for Metonic cycle inaccuracy.
337 (+ 5 (* 8 century)) 25)
338 (* 30 century));; Keeps value positive.
339 30))
340 (adjusted-epact ;; Adjust for 29.5 day month.
341 (if (or (= shifted-epact 0)
342 (and (= shifted-epact 1) (< 10 (% displayed-year 19))))
343 (1+ shifted-epact)
344 shifted-epact))
345 (paschal-moon ;; Day after the full moon on or after March 21.
346 (- (calendar-absolute-from-gregorian (list 4 19 displayed-year))
347 adjusted-epact))
348 (abs-easter (calendar-dayname-on-or-before 0 (+ paschal-moon 7)))
349 (mandatory
350 (list
351 (list (calendar-gregorian-from-absolute abs-easter)
352 "Easter Sunday")
353 (list (calendar-gregorian-from-absolute (- abs-easter 2))
354 "Good Friday")
355 (list (calendar-gregorian-from-absolute (- abs-easter 46))
356 "Ash Wednesday")))
357 (optional
358 (list
359 (list (calendar-gregorian-from-absolute (- abs-easter 63))
360 "Septuagesima Sunday")
361 (list (calendar-gregorian-from-absolute (- abs-easter 56))
362 "Sexagesima Sunday")
363 (list (calendar-gregorian-from-absolute (- abs-easter 49))
364 "Shrove Sunday")
365 (list (calendar-gregorian-from-absolute (- abs-easter 48))
366 "Shrove Monday")
367 (list (calendar-gregorian-from-absolute (- abs-easter 47))
368 "Shrove Tuesday")
369 (list (calendar-gregorian-from-absolute (- abs-easter 14))
370 "Passion Sunday")
371 (list (calendar-gregorian-from-absolute (- abs-easter 7))
372 "Palm Sunday")
373 (list (calendar-gregorian-from-absolute (- abs-easter 3))
374 "Maundy Thursday")
375 (list (calendar-gregorian-from-absolute (+ abs-easter 35))
376 "Rogation Sunday")
377 (list (calendar-gregorian-from-absolute (+ abs-easter 39))
378 "Ascension Day")
379 (list (calendar-gregorian-from-absolute (+ abs-easter 49))
380 "Pentecost (Whitsunday)")
381 (list (calendar-gregorian-from-absolute (+ abs-easter 50))
382 "Whitmunday")
383 (list (calendar-gregorian-from-absolute (+ abs-easter 56))
384 "Trinity Sunday")
385 (list (calendar-gregorian-from-absolute (+ abs-easter 60))
386 "Corpus Christi")))
387 (output-list
388 (filter-visible-calendar-holidays mandatory)))
389 (if all-christian-calendar-holidays
390 (setq output-list
391 (append
392 (filter-visible-calendar-holidays optional)
393 output-list)))
394 output-list)))
395
396 (defun holiday-greek-orthodox-easter ()
397 "Date of Easter according to the rule of the Council of Nicaea."
398 (let ((m displayed-month)
399 (y displayed-year))
400 (increment-calendar-month m y 1)
401 (let* ((julian-year
402 (extract-calendar-year
403 (calendar-julian-from-absolute
404 (calendar-absolute-from-gregorian
405 (list m (calendar-last-day-of-month m y) y)))))
406 (shifted-epact ;; Age of moon for April 5.
407 (% (+ 14
408 (* 11 (% julian-year 19)))
409 30))
410 (paschal-moon ;; Day after full moon on or after March 21.
411 (- (calendar-absolute-from-julian (list 4 19 julian-year))
412 shifted-epact))
413 (nicaean-easter;; Sunday following the Paschal moon
414 (calendar-gregorian-from-absolute
415 (calendar-dayname-on-or-before 0 (+ paschal-moon 7)))))
416 (if (calendar-date-is-visible-p nicaean-easter)
417 (list (list nicaean-easter "Pascha (Greek Orthodox Easter)"))))))
418
419 (defun holiday-rosh-hashanah-etc ()
420 "List of dates related to Rosh Hashanah, as visible in calendar window."
421 (if (or (< displayed-month 8)
422 (> displayed-month 11))
423 nil;; None of the dates is visible
424 (let* ((abs-r-h (calendar-absolute-from-hebrew
425 (list 7 1 (+ displayed-year 3761))))
426 (mandatory
427 (list
428 (list (calendar-gregorian-from-absolute abs-r-h)
429 (format "Rosh HaShanah %d" (+ 3761 displayed-year)))
430 (list (calendar-gregorian-from-absolute (+ abs-r-h 9))
431 "Yom Kippur")
432 (list (calendar-gregorian-from-absolute (+ abs-r-h 14))
433 "Sukkot")
434 (list (calendar-gregorian-from-absolute (+ abs-r-h 21))
435 "Shemini Atzeret")
436 (list (calendar-gregorian-from-absolute (+ abs-r-h 22))
437 "Simchat Torah")))
438 (optional
439 (list
440 (list (calendar-gregorian-from-absolute
441 (calendar-dayname-on-or-before 6 (- abs-r-h 4)))
442 "Selichot (night)")
443 (list (calendar-gregorian-from-absolute (1- abs-r-h))
444 "Erev Rosh HaShannah")
445 (list (calendar-gregorian-from-absolute (1+ abs-r-h))
446 "Rosh HaShanah (second day)")
447 (list (calendar-gregorian-from-absolute
448 (if (= (% abs-r-h 7) 4) (+ abs-r-h 3) (+ abs-r-h 2)))
449 "Tzom Gedaliah")
450 (list (calendar-gregorian-from-absolute
451 (calendar-dayname-on-or-before 6 (+ 7 abs-r-h)))
452 "Shabbat Shuvah")
453 (list (calendar-gregorian-from-absolute (+ abs-r-h 8))
454 "Erev Yom Kippur")
455 (list (calendar-gregorian-from-absolute (+ abs-r-h 13))
456 "Erev Sukkot")
457 (list (calendar-gregorian-from-absolute (+ abs-r-h 15))
458 "Sukkot (second day)")
459 (list (calendar-gregorian-from-absolute (+ abs-r-h 16))
460 "Hol Hamoed Sukkot (first day)")
461 (list (calendar-gregorian-from-absolute (+ abs-r-h 17))
462 "Hol Hamoed Sukkot (second day)")
463 (list (calendar-gregorian-from-absolute (+ abs-r-h 18))
464 "Hol Hamoed Sukkot (third day)")
465 (list (calendar-gregorian-from-absolute (+ abs-r-h 19))
466 "Hol Hamoed Sukkot (fourth day)")
467 (list (calendar-gregorian-from-absolute (+ abs-r-h 20))
468 "Hoshannah Rabbah")))
469 (output-list
470 (filter-visible-calendar-holidays mandatory)))
471 (if all-hebrew-calendar-holidays
472 (setq output-list
473 (append
474 (filter-visible-calendar-holidays optional)
475 output-list)))
476 output-list)))
477
478 (defun holiday-hanukkah ()
479 "List of dates related to Hanukkah, as visible in calendar window."
480 (if (memq displayed-month;; This test is only to speed things up a bit;
481 '(10 11 12 1 2));; it works fine without the test too.
482 (let ((m displayed-month)
483 (y displayed-year))
484 (increment-calendar-month m y 1)
485 (let* ((h-y (extract-calendar-year
486 (calendar-hebrew-from-absolute
487 (calendar-absolute-from-gregorian
488 (list m (calendar-last-day-of-month m y) y)))))
489 (abs-h (calendar-absolute-from-hebrew (list 9 25 h-y))))
490 (filter-visible-calendar-holidays
491 (list
492 (list (calendar-gregorian-from-absolute (1- abs-h))
493 "Erev Hanukkah")
494 (list (calendar-gregorian-from-absolute abs-h)
495 "Hanukkah (first day)")
496 (list (calendar-gregorian-from-absolute (1+ abs-h))
497 "Hanukkah (second day)")
498 (list (calendar-gregorian-from-absolute (+ abs-h 2))
499 "Hanukkah (third day)")
500 (list (calendar-gregorian-from-absolute (+ abs-h 3))
501 "Hanukkah (fourth day)")
502 (list (calendar-gregorian-from-absolute (+ abs-h 4))
503 "Hanukkah (fifth day)")
504 (list (calendar-gregorian-from-absolute (+ abs-h 5))
505 "Hanukkah (sixth day)")
506 (list (calendar-gregorian-from-absolute (+ abs-h 6))
507 "Hanukkah (seventh day)")
508 (list (calendar-gregorian-from-absolute (+ abs-h 7))
509 "Hanukkah (eighth day)")))))))
510
511 (defun holiday-passover-etc ()
512 "List of dates related to Passover, as visible in calendar window."
513 (if (< 7 displayed-month)
514 nil;; None of the dates is visible
515 (let* ((abs-p (calendar-absolute-from-hebrew
516 (list 1 15 (+ displayed-year 3760))))
517 (mandatory
518 (list
519 (list (calendar-gregorian-from-absolute abs-p)
520 "Passover")
521 (list (calendar-gregorian-from-absolute (+ abs-p 50))
522 "Shavuot")))
523 (optional
524 (list
525 (list (calendar-gregorian-from-absolute
526 (calendar-dayname-on-or-before 6 (- abs-p 43)))
527 "Shabbat Shekalim")
528 (list (calendar-gregorian-from-absolute
529 (calendar-dayname-on-or-before 6 (- abs-p 30)))
530 "Shabbat Zachor")
531 (list (calendar-gregorian-from-absolute
532 (if (= (% abs-p 7) 2) (- abs-p 33) (- abs-p 31)))
533 "Fast of Esther")
534 (list (calendar-gregorian-from-absolute (- abs-p 31))
535 "Erev Purim")
536 (list (calendar-gregorian-from-absolute (- abs-p 30))
537 "Purim")
538 (list (calendar-gregorian-from-absolute
539 (if (zerop (% abs-p 7)) (- abs-p 28) (- abs-p 29)))
540 "Shushan Purim")
541 (list (calendar-gregorian-from-absolute
542 (- (calendar-dayname-on-or-before 6 (- abs-p 14)) 7))
543 "Shabbat Parah")
544 (list (calendar-gregorian-from-absolute
545 (calendar-dayname-on-or-before 6 (- abs-p 14)))
546 "Shabbat HaHodesh")
547 (list (calendar-gregorian-from-absolute
548 (calendar-dayname-on-or-before 6 (1- abs-p)))
549 "Shabbat HaGadol")
550 (list (calendar-gregorian-from-absolute (1- abs-p))
551 "Erev Passover")
552 (list (calendar-gregorian-from-absolute (1+ abs-p))
553 "Passover (second day)")
554 (list (calendar-gregorian-from-absolute (+ abs-p 2))
555 "Hol Hamoed Passover (first day)")
556 (list (calendar-gregorian-from-absolute (+ abs-p 3))
557 "Hol Hamoed Passover (second day)")
558 (list (calendar-gregorian-from-absolute (+ abs-p 4))
559 "Hol Hamoed Passover (third day)")
560 (list (calendar-gregorian-from-absolute (+ abs-p 5))
561 "Hol Hamoed Passover (fourth day)")
562 (list (calendar-gregorian-from-absolute (+ abs-p 6))
563 "Passover (seventh day)")
564 (list (calendar-gregorian-from-absolute (+ abs-p 7))
565 "Passover (eighth day)")
566 (list (calendar-gregorian-from-absolute (+ abs-p 12))
567 "Yom HaShoah")
568 (list (calendar-gregorian-from-absolute
569 (if (zerop (% abs-p 7))
570 (+ abs-p 18)
571 (if (= (% abs-p 7) 6)
572 (+ abs-p 19)
573 (+ abs-p 20))))
574 "Yom HaAtzma'ut")
575 (list (calendar-gregorian-from-absolute (+ abs-p 33))
576 "Lag BaOmer")
577 (list (calendar-gregorian-from-absolute (+ abs-p 43))
578 "Yom Yerushalim")
579 (list (calendar-gregorian-from-absolute (+ abs-p 49))
580 "Erev Shavuot")
581 (list (calendar-gregorian-from-absolute (+ abs-p 51))
582 "Shavuot (second day)")))
583 (output-list
584 (filter-visible-calendar-holidays mandatory)))
585 (if all-hebrew-calendar-holidays
586 (setq output-list
587 (append
588 (filter-visible-calendar-holidays optional)
589 output-list)))
590 output-list)))
591
592 (defun holiday-tisha-b-av-etc ()
593 "List of dates around Tisha B'Av, as visible in calendar window."
594 (if (or (< displayed-month 5)
595 (> displayed-month 9))
596 nil;; None of the dates is visible
597 (let* ((abs-t-a (calendar-absolute-from-hebrew
598 (list 5 9 (+ displayed-year 3760)))))
599
600 (filter-visible-calendar-holidays
601 (list
602 (list (calendar-gregorian-from-absolute
603 (if (= (% abs-t-a 7) 6) (- abs-t-a 20) (- abs-t-a 21)))
604 "Tzom Tammuz")
605 (list (calendar-gregorian-from-absolute
606 (calendar-dayname-on-or-before 6 abs-t-a))
607 "Shabbat Hazon")
608 (list (calendar-gregorian-from-absolute
609 (if (= (% abs-t-a 7) 6) (1+ abs-t-a) abs-t-a))
610 "Tisha B'Av")
611 (list (calendar-gregorian-from-absolute
612 (calendar-dayname-on-or-before 6 (+ abs-t-a 7)))
613 "Shabbat Nahamu"))))))
614
615 (defun filter-visible-calendar-holidays (l)
616 "Return a list of all visible holidays of those on L."
617 (let ((visible)
618 (p l))
619 (while p
620 (and (car (car p))
621 (calendar-date-is-visible-p (car (car p)))
622 (setq visible (append (list (car p)) visible)))
623 (setq p (cdr p)))
624 visible))
625
626 (provide 'holidays)
627
628 ;;; holidays.el ends here